Multi-Tech Systems MT3334ZDX - Manual (Page 12)

MT3334ZDX/V Owner's Manual
12
LED Indicators
The MultiModemZDX has ten LED indicators (Figure 2-3) to report status
(such as verifying proper installation) and line activity (such as monitoring
the status of a connection).
Figure 2-3. Front Panel
TD
Transmit Data. The TD LED flashes when data is being transmitted (on
for a space, off for a mark). Signals on this circuit are generated by the
terminal and transferred to the transmitter of the MultiModemZDX. The
transmitting terminal should hold this line in the marking state when no
data is being transmitted, including intervals between characters or
words. The TRANSMIT (TD) LED indicates the status of this circuit.
RD
Receive Data. The RD LED flashes when data is being received (on for
a space, off for a mark). Data signals received from the remote
MultiModemZDX are presented on this line. When no carrier signal is
being received (pin 8 negative), this line will be forced into a marking
condition. The RECEIVE (RD) LED indicates the status of this signal.